Acting Premier Andrew Stoner said today, Wednesday, the announcement was proof the government was progressing with the $10-13 billion motorway from Parramatta to Sydney Airport and the M5.

‘‘I’m pleased to announce that the NSW government has made good progress in the three months since we announced we would go ahead with the 33 kilometre WestConnex project,’’ he said.

Mr Stoner said the body overseeing the project, Sydney Motorways project office, would work with consortiums led by Ferrovial Agroman and Leighton Contractors to develop the route along Parramatta Road.

Plans for the Airport Access Link and Inner West Tunnel would be developed by consortiums led by Thiess and Baulderstone/Bouygues, he said.

‘‘We are determined to ensure the WestConnex motorway is amongst the best in the world,’’ Mr Stoner said.

The O’Farrell government has promised $1.8 billion for the WestConnex project, with about $7b expected to be raised by new tolls.

Other financing options are still being investigated by the government.

Roads Minister Duncan Gay said the ‘‘nationally and globally recognised firms’’ would help ensure a ‘‘robust business case’’ was submitted to the government by mid year.

‘‘The project office has been formed from experts from across the public and private sectors who will prepare a business case proving WestConnex is necessary, achievable and affordable,’’ he said.

Mr Gray said Ernst & Young had been appointed to carry out economic modelling for WestConnex and Macquarie Bank would investigate financing options.

The consortiums working on the Airport Access Link and Inner West Tunnel include AECOM, Aurecon, Bamser, Conybeare Morrison, GHD, Hyder, Halcrow, Pells Sullivan Meynink, SMEC, Turner and Townsend and Urbis.